Various compositions are known to be useful as treating agents to provide surface effects to substrates. Surface effects include repellency to moisture, soil, and stains, and other effects, which are particularly useful for fibrous substrates such as fibers, fabrics, textiles, carpets, paper, leather, and other such substrates. Many such treating agents are fluorinated polymers or copolymers.
Fluorinated polymer compositions having utility as fibrous substrate treating agents generally contain pendant perfluoroalkyl groups which are generally attached by various connecting groups to polymerizable groups not containing fluorine. The resulting monomer is then generally copolymerized with other monomers, which confer additional favorable properties to the substrates. Various specialized monomers may be incorporated to impart improved cross-linking, latex stability and substantivity. Since each ingredient may impart some potentially undesirable properties in addition to its desirable ones, the specific combination is directed to the desired use.
U.S. Patent Application 2005/0095933 discloses compositions for treating textiles formed by combining a repellent component, a stain resist component, a stain release component, and particles. Various commercially available fluorinated polymers are employed as the repellent component and the particles are inorganic oxides or basic metal salts. The fluorinated polymers and particles are separately added to a solution, and thus represent a mixture of the polymer and particle, which is applied to the substrate to be treated.
Vinylidene chloride is commonly used in commercially available fluorinated polymers used to treated substrates for surface effects. It is well known that major by-product of polymers containing VDC is hydrochloric acid. Liberated hydrochloric acid not only contributes to the degradation of the polymer, but also may cause de-colorization of the treated textiles and may cause yellowing. In addition, the National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit for vinylidene chloride of the lowest feasible concentration (0.4 ppm, limit of quantitation). NIOSH also considers vinylidene chloride to be a potential human carcinogen. Thus, vinylidene chloride used in treating substrates should be limited.
The expense of the fluorinated polymer dictates that it be used at lower levels in treating substrates to provide surface effects. However, reducing the level of fluorine by using polymers containing shorter chained perfluoroalkyl groups of six carbons or less has not been commercially successful. Thus there is a need for compositions for treating substrates which do not contain vinylidene chloride and impart surface effects including durable water repellency and oil repellency, which maintain levels of performance, while using less of the expensive fluorinated component. The present invention provides such a composition.